Beta hemolytic Streptococcus, the causative agent of strep throat, is one of the most common ailments of children from 5 to 18 years of age. Current estimates indicate that in the United States alone there are 7.5 million cases of strep throat and over 25 million cases of sore throat. Doctor's visits for sore throats are a major burden on the pediatric health care system and considerable time is lost from work by parents that may spend an entire day at home for a scheduled visit to the doctor.
Current professional care tests on the market include cultures that can take 1-2 days and rapid tests that are based on antibodies and lateral flow technologies.
Current professional care rapid tests do not have applicability for consumer use for several reasons: (1) antibody-based tests have very poor sensitivity because it is difficult to collect the swab sample at the wound site at the back of the inflamed tonsils; (2) presenting a swab at the back of the throat is a choking risk for a child; and (3) many antibody-based tests are too kit-like and have too many steps for the consumer to properly follow instructions. As a result, there is considerable demand and unmet need for a sensitive consumer diagnostic test for strep throat.
The presence of β-hemolytic Streptococci (also known as group A Streptococci or Streptococcus pyogenes) in wounds causes infection and prevents healing at levels significantly lower than the 106 bacteria per gram of tissue that is often considered the level leading to infection (see Steed, David L et al. Guidelines for the Treatment of Diabetic Ulcers. Wound Rep Reg. 2006, 14: 680-92; and Edwards, Ruth and Keith G. Harding. Bacteria and Wound Healing. Curr Op Infec Dis. 2004, 17: 91-96; the teachings of which are incorporated herein by reference in their entirety). Therefore, the presence of β-hemolytic Streptococcus is undesirable at any level and early detection is of the essence in order to avoid the possibility of severe cellulitis, sepsis, or streptococcal toxic shock syndrome (see O'Loughlin, Rosalyn E et al. The Epidemiology of Invasive Group A Streptococcal Infection and Potential Vaccine Implications: United States, 2000-2004. Clin Infec Dis. 2007, 45: 853-62; the teachings of which are incorporated herein by reference in their entirety). Thus, there is a need for a simple and rapid assay that can detect low levels of Group A Streptococcus organisms, for example, in wounds.